# Controller Details ![](https://1584734385-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LIeRq0woQQZog4Wx9KA%2F-LvOQqWxkBugJUFjwetk%2F-LvOQyPDgfXPOznL-QxH%2Fcontroller-assembly-v02-min.png?alt=media\&token=e9c90c59-ac47-4b07-835a-cfdbb8aed71a) The EPOC Flex controller pictured above has 16 channels on the left + CMS input and 16 channels on the right + DRL output. These channels are connected in two rows A-H and J-Q with the position above the CMS/DRL empty. The power switch is located next to the USB connector on the bottom edge of the unit, turn it to the right to turn on and left to turn it off. There is a multifunctional LED located below the logo to indicate charging or power on. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://emotiv.gitbook.io/epoc-flex-user-manual/controller/controller-assembly.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.